Mastercard has revealed that it is in dispute with the Australian Tax Office after one of its local subsidiaries was slapped with amended tax assessments on past earnings.The disclosure was made in accounts filed with Australian regulators on 1 June by Mastercard Australia Holding Pty Ltd, the head tax entity for the global card company's local operations.In notes to the accounts, the holding company revealed that one of its controlled entities had been asked to pay A$22.8 million to cover its tax obligations over three years beginning in January 2010.The local subsidiary has objected to the revised tax assessments that relate to the pricing of services it provided to another Mastercard business."A subsidiary of the group is currently in dispute with the Australian Taxation Office as to the price at which it has provided services to a related company and assigned certain contracts to it," the holding company states in its latest financial accounts."The ATO has issued amended assessments for the period from 1 January 2010 to 31 December 2012 which total A$22.8 million, including interest and penalties."The subsidiary has objected to the amended assessments and has paid an amount of AU$7.1 million pending resolution of the dispute." Mastercard maintains that its pricing methodologies are in accordance with OECD guidelines and believes its subsidiary will successfully defend its position.Mastercard's local holding company controls 18 businesses, including entities operating in Australia, China, Taiwan, Singapore, Japan and New Zealand.The group accounts do not name which of the subsidiaries was in dispute with the ATO.However, the ATO in recent years has published the tax details of a company known as Mastercard Asia Pacific (Australia) Pty Ltd.According to a document released by the ATO a few years ago this subsidiary in 2014 paid tax of $1.86 million on taxable earnings of $11.7 million. This equated to an effective tax rate of around 16 per cent.The Federal Government is expecting corporate tax revenue to rise significantly over the next four years partly as a result of new measures aimed at stamping out methods for minimising tax.A focus of the ATO's heightened scrutiny of global companies operating in Australia has been to tighten transfer pricing rules that regulate related-party payments.Mastercard Australia Holding Pty Ltd and its controlled entities reported net operating losses last year and in 2016, which allowed the group to claim income tax credits.In the 12 months to the end of December last year, the holding company reported a loss before tax of $39.2 million.A tax benefit of $14 million improved the bottom line loss to $25.2 million.